Tiwari, B.B., et al. “Electrophoretic Studies on Determination of Stability Constants of Zn(II) and Cd(II) Mixed Complexes (M-Methionine-Cysteine System) ”. Asian Journal of Chemistry, vol. 5, no. 1, Mar. 2010, pp. 6-10, https://asianpubs.org/index.php/ajchem/article/view/24742.